Skew rays in optical fibers

In order to justify the use of meridional analysis, the authors solve the Eikonal equation without approximationin two cases of index profile. Limit conditions are studied and attention is given to skew rays with inclination over the fiber axis greater than the critical angle of the meridional case. It is shown that skew rays introduce a queue in the impulse response of a fiber. In the case of solid state laser sources, they do not carry significant energy, and then can be neglected.